Washington: US Secretary of State John Kerry and Chinese Foreign Minister Wang Yi are to discuss on Wednesday the mounting political crisis in Hong Kong that has sparked mass protests, US officials said.

Pro-democracy protestors have seized Hong Kong`s business district since Sunday and thousands of demonstrators have rejected demands from the city`s chief executive to end the sit-in.

"This is obviously a prominent issue in the news, one the secretary is well aware of, and I expect it will be a part of this discussion," State Department spokeswoman Jen Psaki told reporters in Washington.

Psaki said the unrest, the most intense in the Chinese territory since 1997, is "certainly something that could be on the agenda" during the discussions, which were scheduled before the protests kicked off.

Demonstrators in Hong Kong are demanding free elections and say China should not be allowed to select candidates for the spot of chief executive in a 2017 vote.

The United States said it believed "the legitimacy of the chief executive would be greatly enhanced" if protesters demands for universal suffrage were fulfilled.

At the US Congress, lawmakers were critical of Hong Kong police, who used tear gas in a failed attempt to move the thousands of demonstrators at the weekend.

The head of the Senate Committee on Foreign Relations, Robert Menendez, wrote to Hong Kong Chief Executive Leung Chun-ying urging him to respect protestors` right to demonstrate.

Meanwhile, Republican Chris Smith, head of the Subcommittee on Human Rights, said a special group would be created to follow human rights in Hong Kong.